1. Field of the Invention
The invention relates to an open-end spinning device consisting of an electric motor of which the rotor together with the spinning container are fastened on a hollow shaft, this hollow shaft being mounted on a bearing journal.
2. Description of the Prior Art
A device of this type is known, for example, from Swiss patent specification No. 598,503.
The requirements demanded of textile machines working according to the open-end spinning process are essentially as follows:
1. a high production capacity per machine unit; PA1 2. a long life; PA1 3. short idle times; PA1 4. long inspection intervals; PA1 5. a low noise level; and PA1 6. a high degree of flexibility for a wide yarn-count range.
However, these requirements can be met only with machine constructions which essentially allow fault-free spinning at very high speeds and rapid exchangeability of the spinning containers with different dimensions, whilst ensuring minimum idle times. The necessary robustness of the constructions and the necessary quiet running of the rotors at high speeds, which involve the mounting of the rotors, are important preconditions for this.
Swiss patent specification No. 598,503 describes a spinning unit of the type mentioned above. In this, the rotor shaft forms with the rotor of the electric motor, together with roller bearings, a constructional unit which is accommodated fixedly in the housing part of the machine by means of gluing and, if appropriate, by means of additional mechanical tongue-and-groove anchoring.
However, the use of roller bearings for high rotor speeds presents problems, since these can lead to losses due to friction which are converted into heat, which is transmitted to the rotor and the spinning container. Although the construction according to Swiss patent specification No. 598,503 provides for the exchangability of the rotor part in textile operation, this specification does not describe the method of putting this into effect. However, it would seem to involve a relatively high outlay in terms of work and time.
Furthermore, because of the spinning process, residues of fiber material remain adhering, in uneven distribution, in the spinning groove of the spinning container, and particles of dirt settle in the spinning groove. As a result, the mass of the spinning container, of the hollow shaft and of the rotor armature, which rotates at high speed, has its quiet running disturbed because of an undefined imbalance which is variable as a function of time both in amount and in direction. The wobbling movements of the rotor, which result from this, exert constraining forces on rigidly arranged radial bearings and have a destructive effect on bearing systems of this type.